Copper resistance in Candida guilliermondii strain DS31

摘要

Candida guilliermondii strain DS31 could resist copper (Cu) up to 25 mM on a complex medium. Cells turned bright blue on Cu(II)-amended medium and accumulated 5.5% Cu(II) on dry weight basis. While in the resistant strain Ds31 most of the Cu(II) could be extracted by simple EDTA treatment, a Cu(II)-sensitive derivative CS2 retained significant amount of Cu(II) even after extraction with EDTA. Ultrastructural studies indicated deposition of electron-denselysis granules in the cell wall. Cu(II) also induced plasmolysis and vacuole formation. We report here orpho-logical and ultrastructural changes induced by Cu(II) in the yeast strain. A possible mechanism of copper resistance has also been discussed.